1. Field of Invention
The present invention relates to a digital image capture device and a brightness correction method thereof, and more particularly to a method for correcting the brightness value of a shot object at different distances and a digital image capture device thereof.
2. Related Art
With the development of digital cameras, photography is no longer an expensive consumption. Users may shoot desired images at will to record a memorial moment or scene. Due to physical properties, the lens set in the digital image capture device may cause the problem of non-uniform brightness distribution during the imaging of the shot object under the light source. In other words, the center of the digital image is brighter than the periphery. Meanwhile, if the strobe is used for compensating the brightness, the non-uniform brightness distribution becomes even more apparent. The reason is that the strobe reflects all the lights from the light source onto the shot object through the reflecting plate, and the strobe and the lens set are located at different positions, so that the shot object is under varied impacts due to its distance from the camera. If the digital image capture device is closer to the shot object, the brightness distribution of the digital image is increased, and vice versa. In order to solve the above problem of brightness distribution, a shading table is provided, in which a digital image is represented by a two-dimensional array and brightness compensation is performed on the digital image through digital gain.
FIG. 1 is a schematic flow chart of the prior art. A digital image is pre-captured (Step S110). It is determined whether to turn on a strobe or not (Step S120). If the strobe is shot, an emission time of the strobe is estimated (Step S130). If the strobe is not shot, the digital image is directly shot and a shading table is loaded for adjusting the digital image (Step S140). If only a shading table is applied to all the shooting environments, the problem that the long-shot gain is too much while the close-shot gain is insufficient may occur to the digital image at different focusing object distances, and vice versa. In this manner, the modified digital image appears unnatural.